HIGHER HARMONIC WAVE COMPONENT MEASURING DEVICE

• Main Author: SHIODA TOSHIAKI
• Format: Patent
• Language: English
• Published: 14.06.2012
• Subjects: MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To provide a higher harmonic wave component measuring device which reduces a higher harmonic wave component that is not originally included in an input waveform, when an FFT operation is performed, and thus obtains a precise measurement result.SOLUTION: A higher harmonic wave component measuring device comprises: A/D converters 2 and 5 for converting an analog input signal into digital data based on a sampling clock; zero-cross detectors 3 and 6 for detecting a zero-cross of the analog input signal; an interpolation timing generator 40 for obtaining a fundamental frequency of the analog input signal based on a detection signal from the zero-cross detector and generating an interpolation timing of a frequency being integral times the fundamental frequency; an interpolation calculator 49 for obtaining a value at the interpolation timing of the digital data by performing a spline interpolation; and an FFT calculator 43 for calculating a fundamental wave component and a higher harmonic wave component of the analog input signal by performing an FFT calculation on the interpolated value of the digital data.